Expendable perforating apparatus



June 25, 1963 w. B. BLAIR I 3,094,930

EXPENDABLE PERFORATING APPARATUS Filed May 18, 1960 4 Sheets-Sheet 1 W; for? 5. 5/0 INVEN TOR.

I %wx2a W. B. BLAIR EXPENDABLE PERFORATING, APPARATUS June 25, 1963 4 Sheets-Sheet 2 Filed May 18, 1960 W//7 fan 5. fi/a/r INVENTORI,

ATTOAA/Er June 25, 1963 w. B. BLAIR EXPENDABLE PERFORATING APPARATUS 4 Sheets-Sheet 3 Filed May 18, 1960 INVENTOR.

Afro/Mir 7 June 25, 1963 w. B. BLAIR EXPENDABLE PERFORATING APPARATUS I Filed May 18, 1960 4 Sheets-Sheet 4 INVENTOR.

United States Patent Ofiiee 3,094,930 Patented June 25, 1963 3,094,930 EXPENDABLE PERFORATING APPARATUS Wlnton B. Blair, Houston, Tex., assignor to Schlumberger Well Surveying Corporation, Houston, Tex., a corporation of Texas Filed May 18, 1960, Ser. No. 29,919

12 Claims. (Cl. 102-20) This invention relates to well perforating apparatus and, more particularly, to expendable type perforating apparatus for use in well strings of small diameter.

In many types of well completion presently practiced, it is both necessary and desirable that a perforating apparatus for producing perforations in formations be passed through'a tubing having a diameter on the order of two or two and one-half inches. Particularly in the case where the perforating apparatus is operated within a tubing of small diameter, it is most desirable to reduce the amount'of debris of the perforating apparatus that is left in the tubing.

Many factors, of course, enter into the design and selection of perforating apparatus for passage through a tubing and the amount of debris a perforating apparatus will produce, but, in general, the types of perforating apparatus may conveniently be divided into a carrier type apparatus and a capsule type apparatus. The advantages and disadvantages between the two types of apparatus need not be described herein, it being sufiicient to specify that the present invention relates particularly to perforating apparatus of the capsule type.

Generally, in a capsule type perforator apparatus, a number of shaped charges in capsule containers are linked to one another by linking connections on the containers to form a chain or linked assembly of charges. A suitable detonating cord initiating means is interconnected between the various containers to detonate the shaped charges. The debris that is produced from this capsule type perforator results mainly from two sources, namely,

the capsule container itself and the linkage connections necessary to interconnect the capsules. In the present invention, an assembly of capsule type shaped charges is presented in which the debris left in the borehole is resultant solelyfrom the capsule containers, a support for interconnecting the capsule containers being retrievable. In this manner, the amount of debris left in the borehole can be considerably reduced.

Also, in certain instances, it is desired to orient the shaped charges in a given direction in a foolproof manner. Thus, in accordance with the present invention, the capsule containers can be arranged only in one manner in the support so that the shaped charge arrangement or orientation is always the same.

Accordingly, it is an object of the present invention to provide new and improved capsule type, shaped charge perforating apparatus arranged for minimizing debris and for assembly in only one manner.

Apparatus in accordance with the present invention includes an elongated and continuous strip member or support having a plurality of openings spaced from one another along a length of the strip member. A plurality of capsulated shaped charge devices are provided, each having an intermediate section with a portion sized to be received in a corresponding strip opening and having forward and rearward ends along the firing or jet axis of the charge devices. About the openings in the strip member are radially extending slots. Attaching means for the charge devices includes a set of radially extending lug portions on the intermediate section which are spaced axially from one another a distance corresponding generally to the thickness to the strip member so that the lug portions may be inserted into the slots and rotated, thereby permitting the lugs to engage opposite sides of the strip. The strip member and charge devices are so arranged that only the rearward ends of the charge devices can be inserted through the openings in the strip and the lugs can be inserted into the slots from only one side of the strip member so that the forward ends of the devices all face in the same direction. To insure the rotative positioning of the shaped charge device in the strip, detonating cord means extend along the length of the strip member and is received within the rearward ends of the shaped charge devices so as to hold the devices in a rotatively attached position.

The novel features of the present invention are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by way of illustration and example of certain embodiments when taken in conjunction with the accompanying drawings in which:

FIG. 1 illustrates a view of a portion of apparatus embodying the present invention disposed in a well bore;

FIG. 2 is a view in cross section taken along line 2-2 of FIG. 1;

FIG. 3 is an enlarged side view taken longitudinally of a portion of the apparatus embodying the present invention;

FIG. 4 is a plan view taken of a portion of the apparatus embodying the present invention;

FIG. 5 is a perspective view of a shaped charge device from its rearward end;

FIG. 6 is a side view of a shaped charge device;

FIGS. 7-10 are enlarged, fragmentary views in partial cross section of one embodiment of the present invention, the view of FIG. 7 being inverted;

FIGS. 11-13 are enlarged, partial views in cross section of another embodiment of the present invention;

FIGS. 14, 15 are enlarged, partial views in cross section of another embodiment of the present invention;

FIGS, 16'; 17 are enlarged, partial views in cross section of another embodiment of the present invention.

Referring now to FIGS; 1 and 2, a borehole 20 is shown traversing the earth formations 21 and has a casing 22 of ferromagnetic material suitably cemented thereto- An assembly 23 comprised of a magnetic orienter 24 and a perforating apparatus 25 is adapted for passage through small diameter tubing (not shown) by means of a cable 26 and winch (not shown) in the customary manner.

The magnetic orienter 24 may include permanent magnets 27 (FIG. 2) arranged to develop a resultant force of magnetic attraction in a radial direction which intersects a generatrix of contact between the magnetic orienter 24 and the casing 22, the radial direction being schematically represented by the arrow 28 in FIG. 2..

The perforating apparatus 25 includes an elongated strip member 30, which holds a number of encapsulated shaped charges 31, the charges being arranged to face in the same direction and the direction of firing being oriented with respect to the force of magnetic attraction so that the shaped charges will fire directly into the casing 22.

Referring now to FIGS. 3 and 4, the carrier or, more specifically, the elongated strip member 30 is shown which may be constructed of common, ductile and moderately flexible sheet material, for example, steel and have, say, a width of 1 /8" and a thickness of Hence, the width of the strip is suitable for passing through a two-inch diameter tubing. The length of the strip 30 may be any suitable or desired length, for example, a convenient length being about twelve feet. As far as material for the which may be punched out of the strip member 30 generally along its central axis 34 and preferably at a uniform spacing, that is, the spacing between the holes 33 being such as to provide a desired number of openings per foot of strip. For example, on three-inch centers, four holes per foot may be provided.

In FIGS. 3 and 4, only one such opening 33 will be described since all of the openings are identically arranged. In 'FIG. 3, a side view of the strip member 30 is shown, while in FIG. 4 a rear view of the strip member 30 is shown. The opening 33 is provided with a pair of radially extending slots 33a, 33b which are respectively disposed at180 from one another along a diametrical axis 33c which intersects the central axis 34 of the strip as well as the center of the opening 33 to provide a symmetrical arrangement. Axis 33 is disposed at a preferred negative angle of 30 relative to the central axis 34 of the strip member for reasons which will hereinafter become more apparent. Intermediate of the acute angle between axes 33c and 34, the strip member has radial extensions 35, 36 extending inwardly from the diameter D" of opening 33 to a smaller diameter d, the extensions being disposed immediately adjacent to the respective slots 33a and 33b.

Referring now to FIGS. and 6, the capsule devices or encapsulated shaped charge indicated by the numeral 31, which are to be received by the large diameter openings 33, are identical in construction; hence, for convenienc'e of description, only one such device will be described. Device 31 has a forward end 41 and a rearward end 42 disposed along a central axis 43 and encloses a conventional explosive shaped charge (not shown) provided with the usual conically shaped liner (not shown) opening forwardly along a charge axis. The outer configuration of the device 31 is generally conical and includes the hemispherical forward end 41, and an intermediate section 44 including cylindrical surfaces 44a, 44b of dififerent diameters and a tapered surface 45, the cylindrical surface 44b having the smaller diameter and adjoining the tapered surface 45. The tapered surface 45 is inclined from the cylindrical surface 44b inwardly towards the central axis 43 of the device to the rearward end 42, which is generally cylindrical with a relatively small diameter. The diameter of cylindrical surface 44a is generally greater than diameter D of opening 33, while the diameter of cylindrical surface 44b is just slightly less than the diameter D of opening 33. Hence, only the rearward end 42 of the capsules can be inserted in the opening 33 of the strip member.

On the intermediate section 44 of a capsule 31 is a pair of attaching devices 47 and 48 in the form of rectangularly shaped projections which extend outwardly or radially of the section 44 along an axis which is perpendicular to and intersects the central axis 43 of the charge device. The projections 47, 48 are slotted to form forward lugs 47a, 48a and rearward lugs 47b, 48b. The aforesaid forward and rearward lugs are respectively spaced axially of one another a distance just slightly greater than the thickness of the strip 30. The bottom surfaces 49 between the lugs are spaced diametrically from one another a distance just slightly less than the diameter D of the opening 33. The width of the rearward lugs 47a, 48a is less than the width of slots 33a, 33b and the radial extension of the lugs 47a, 48a is such that they may pass through the slots 33a, 33b and yet extend beyond the diameter D of the opening 33.

A- transverse section of the capsule along the tapered surface 45 has the diameter d (FIG. 6) and this section lies-inwardly of the slots between the aforesaid forward and rearward lugs for reasons which will become apparent from the discussion to follow.

It willbe appreciated that the rearward lugs 47b, 48b can be received through slots 33a and 33b and rotated counterclockwise, as seen in FIG. 4, thereby to latch the capsule device 31 to the strip member. To insure against tilting or rocking of the capsule device in the strip member, a pair of radially extending projections 50, 51 is located along an axis disposed at an angle of from the axis of the projections 47, 48 and extends outwardly from the intermediate section 44. The pair of projections 50, 51 likewise may be rectangularly shaped and extends outwardly a distance greater than the diameter of the opening 33 and has rearward flat surfaces 52, 53 (one in FIG. 6, one in FIG. 5) which lie in a plane perpendicular to the central axis 43 of the shaped charge device and corresponding to the plane in which the inner or rearward surfaces of the forward lugs 47a, 48a lie. In this manner, four equally spaced contact surfaces are provided against one side of the strip member 30, thereby preventing rocking or tilting of the devices 31 when they are attached to the strip.

The rear end 42 of each capsule device is provided with a slot-like opening 54 formed from spaced, parallel wall surfaces opening into a bore 55 of greater diameter than the spacing between wall surfaces. The bore 55 has a diameter roughly equal to the diameter of a detonating cord 56 and the spacing between the parallel walls is such that the detonating cord 56 may be squeezed into the bore 55 between the parallel walls and then expand in the bore, thus being firmly secured in the rear end of the device. The axis of the bore 55 is disposed perpendicular to the central axis 43 of the device and parallel to the axis of the projections 47, 48.

Referring now to FIGS. 7-10, the principles of the present invention will become more apparent. Since the inward extensions 35, 36in openings 33 are similar, only one extension need be discussed. Extension 35 may be formed in the strip member by a coining or sizing operation in which a corner edge portion of the slot 33a in opening 33 is upset or deformed to form a curved protrusion extending inwardly of opening 33 with a tapered or beveled surface 57 extending generally from the front face of the strip member toward the remaining or rear face. As shown in the FIG. 4, extension 35 extends inwardly of the diameter D of opening 33 to a lesser diameter d. The resultant upset configuration of extension 35 is such that the extension has a tapering thickness which decreases inwardly from the opening 33 to the tip of the extension 35.

Referring now to FIG. 10, it will be shown Why a capsule cannot be inserted into the opening from the rear side of the strip which faces the arrow 61. Also, since both slots 33a, 33b are symmetrical, only one will be discussed for clarity of presentation. Considering now the rear end of a capsule moving in the direction of arrow 61, the portion of the tapered surface 45 (shown in dashed lines) with a diameter d will engage the portion of extension 35 (which extends to a diameter d and lies in the plane of the rear side of the strip member) before the rearward lug 48b is completely through the slot 33b in opening-33. Thus, the capsule 31 cannot be inserted in the strip member from its rear face in this manner because of the mechanical interference of lug 48b 'with the strip 30. It will be appreciated that extension 36, lug 47b and slot 33a cooperate in the same manner as above described.

However, as shown in FIG. 9, a capsule can be inserted into opening 33 from the other or front side of the strip. Iience, considering the rear end of the capsule as moving in the direction of arrow 60 into the opening 33, the portion of the tapered surface 45 of the capsule which has a diameter d does not engage extension 35 until the rearward lug 48b is completely through the slot 33b in opening 33. Thus, the capsules can be individually disposed in the strip openings 33 from only one side (the front side) of the strip 30. Because of the extensions 35 and 36, the capsules, when positioned in the strip, can be rotated in only one direction until the projections 47, 48

engage the extensions 35, 36. Because of the angular displacement of the slots 33a, 33b relative to the longitudinal axis 34 of the strip member 30, the projections 47, 48 on the capsules may be substantially aligned with the central axis 34. Thus, the detonating cord 56 can be threaded linearly through the successive slots 54 in the capsules and located to one side of the strip and will, of course, prevent rotational movement of the capsules. The detonating cord 56 is thereby disposed lengthwise of the strip and common string ties 63 (FIG. 1) may be employed to tautly fix the detonating cord 56 relative to the strip member 30.

Referring now to another embodiment of the present invention, as shown in FIGS. 11-13, extension 35a (and likewise an extension 36a, not shown) may be upset and bend outwardly from the plane of the strip member 30 while leaving a portion of the extension 35a lying between the outer surfaces of the strip members. The upset edge 64 of the extension 35a extends inwardly of the opening 33 to the diameter d. Thus, as shown in- FIG. 12, the portion of the capsule device with a diameter d will engage extension 350: if inserted from the direction 60 so that lug 4811 does not pass through the slot 33a.' However, as shown in FIG. 13, the lug 48b will pass through slot 33a if the capsule device is inserted in the direction 61, since the extension 3511 does not contact the portion of the capsule device with the diameter a.

Referring now to FIGS. 14 and 15, extension 3% is shown wherein the extension is formed simultaneously with the punching of the opening 33. In this embodiment, extension 35b is crimped and cut by the punching die to 'be displaced outwardly of the surface of the strip member and inwardly to a diameter d. This embodiment would function similar to the embodiment of FIGS. 7-12.

Referring to FIGS. 16 and 17, extension 350 is shown wherein the extension is formed in the die punching operation and the extension is aligned with the slot 33a. The extension is displaced outwardly of the surface of the strip a sufiicient distance to accommodate lug 47b of acapsule.

Thus, the lugs can be inserted from one side only; however, it will be appreciated that the ex-' tension 35c will not limit the rotative movement of l the capsules in the strip.

While particular embodiments of the present invention have been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such 1 changes and modifications as fall within the true spirit and scope of this invention.

. What isclaimed is:

1. Well perforating apparatus comprising an elonl gated flat, strip-like support member having generally circular openings spaced from one another along its length; capsulated shaped charges received in said open ings, each including a container having a cross section tapering rearwar-dly toward a rearward end having a blasting cord slot therein and each sized for rearward reception in an opening, each container having attaching portions spaced about its periphery engaging the front and rear faces of said support member about said opening for attaching containers thereto, each container and said support member about said openings having abutment portions interengageable in one rotative position of a container in an opening to limit further relative rotation ing slots about each of said openings to accommodate the attaching portions of each container which engage its rear face for removal of said shaped charge only when a container is rotated away from said one position, and blasting cord means received in said blasting cord slots for retaining a container in said one position.

2. Well perforating apparatus comprising a strip-like support member having generally circular openings spaced from one another along its length; capsulated shaped charges received in said openings, each including a container having a generally circular cross section tapering rearwardly toward a rearward end having a blasting cord slot and each sized for rearward reception in said openings, each container having attaching portions engaging the front and rear faces of said support member about said openings for attaching containers thereto, each container and said support member about said opening having abutment portions interengageable in one rotative position of a container in an opening to limit further relative rotation in a given sense thereby facilitating a rotative alignment of each container relative to said support member, said support member abutment portions and said container abutment portions being correlated relative to said blasting cord slots so that said blasting cord slots are aligned with respect to one another lengthwise of said support member when said containers are in said one rotative position; said support member having radially extending slots about said openings to accommodate the attaching portions of each container which engage its rear face for removal of said shaped charge only when a container is rotated away from said one position, and blasting cord means received in said blasting cord slots for retaining said container in said one position, said abutment portions of said support member extending radially inward from said opening and having a relief relative to the front face of said support member, each container having a relief complementary to said abutment portion relief whereby a container is received in an opening for attachment to said strip member only by insertion of the, rearward end of a container through the opening on the front face of said support member.

3. Perforating apparatus for use in a well bore comprising a plurality of lcapsulated shaped charges each 1 having spaced radial projections and a rear end with a to receive said shaped charges, said strip member having radially extending slots about said openings to receive said projections, said projections having grooves therein to form lugs to engage opposite sides of said strip, said strip member having projections about said openings extending radially inward therefrom and having a relief relative to one face of said strip member, said shaped charges having reliefs complementary to said support member reliefs whereby said shaped charges are received in said openings for attachment to said strip member only by insertion of the rear ends of said shaped charges through the openings on one face of said strip member, thereby permitting alignment and securing of said shaped charges in said strip member so as to fire in only one direction, and a detonating cord receiving in said detonating cord receiving openings in the rear ends of said shaped charges. a

4. Perforating apparatus for use in a well bore comprising a plurality of capsulated shaped charges having spaced radial projections and a rear end with a detonating cord receiving opening, a detonating cord sized for retention in said primacord receiving openings in the rear ends of said shaped charges, and an integral strip of infrangible material of a given thickness and having openings spaced along its length to receive said shaped charges, said strip having. radially extending slots about said openings to receive said projections, said projections having grooves therein to form lugs to engage 'op-- posite sides or" said strip when said shaped charges are rotated relative to a said strip, said strip having radial extensions extending inwardly of said openings to a lesser given diameter than the normal diameter of said openings, said extensions being offset relative to at least one plane defined by an outer side surface of said strip so that said openings have portions of dififerent diameters adjacent the respective side surfaces of said strips, said shaped charges having portions of different diameters corresponding generally to the portions of diiferent diameters of said openings, thereby permitting insertion of said charge devices from only one side of said strip, said detonating cord extending along the length of said strip and through said receiving openings so as to hold shaped charges in fixed rotated position, thereby preventing release of said shaped changes from said strip.

5. Perforating apparatus for use in a well bore comprising a plurality of capsulated shaped charges having spaced radial projections and a rear end with a detonating cord receiving opening, a detonating cord sized for retention in said primacord receiving openings in the rear ends of said shaped charges, and an integral strip of infrangible material of a given thickness and having openings spaced along its length to receive said shaped charges, said strip having radially extending slots about said'openings to receive said projections, said projections having grooves therein to form lugs to engage opposite sides of said strip when said shaped charges are rotated relative to a said strip, said strip having radial extensions adjacent to said slots and extending inwardly of said openings to a lesser given diameter than the normal diameter of said openings, said extensions being offset relative to at least one plane defined by an outer side surface of said strip so that said openings have portions of diflerent diameters adjacent the respective side surfaces of said strips, said shaped charges having portions of different diameters corresponding generally to the portions of different diameters of said openings, thereby permitting insertion of said charge devices from only one side of said strip, said detonating cord extending along the length of said strip and through said receiving openings so as to hold shaped charges in fixed rotated position, thereby preventing release of said shaped charges from said strip.

6. Perforating apparatus for use in a well bore comprising a plurality of capsulated shaped charges having spaced radial projections and a rear end with a blasting cord receiving opening, a blasting cord sized for retention in said primacord receiving openings in the rear ends of said shaped charges, and an integral strip of infrangihle material of a given thickness and having openings spaced along its length to receive said shaped charges, said strip having radially extending slots about said openings to receive said projections, said projections having grooves therein to form lugs to engage opposite sides of said strip when said shaped charges are rotated relative to a said strip, said strip having radial extensions extending inwardly of said openings to a lesser given diameter than the normal diameter of said openings, said extensions being tapered relative to at least one plane defined by an outer side surface of said strip so that said openings have portions of different diameters adjacent the respective side surfaces of said strips, said shaped charges having tapered portions corresponding generally to the tapered extensions in said openings, thereby permitting insertion of said charge devices from only one side of said strip, said blasting cord extending along the length of said strip and through said receiving openings so as to hold shaped changes in fixed rotated position, thereby preventing release of said shaped charges from said strip. 7

7. Perforating apparatus for use in a well bore comprising a plurality of capsulated shaped charges having a pair of spaced radial projections and a rear end with a blasting cord receiving opening, a prim-acord sized for retention in said blasting cord receiving openings in the rear ends of said shaped charges, and an integral strip of infrangible material of a given thickness and having openings spaced along its length to receive said shaped charges, said strip having a pair of radially extending slots about said openings to receive said projections, said projections having grooves therein to form lugs to engage opposite sides of said strip when said shaped charges are rotated relative to a said strip, said snip having a pair of radial extensions extending inwardly of each of said openings to a lesser given diameter than the nor-. mal diameter of said openings, said extensions being tapered relative to at least one plane defined by an outer side surface of said strip so that said openings have portions of different diameters adjacent the respective side surfaces of said strips, said shaped charges having tapered portions corresponding generally to the tapered extensions in said openings, thereby permitting insertion of said charge devices from only one side of said strip, said blasting cord extending along the length of said strip and through said receiving openings so as to hold shaped charges in fixed rotated position, thereby preventing release of said shaped charges from said strip.

8. Perforating apparatus for use in a well bore comprising a plurality of capsulated shaped charges having spaced radial projections and a rear end with a blasting cord receiving opening, a blasting cord sized for retention in said primacord receiving openings in the rear ends of said shaped charges, and an integral strip of infrangible material of a given thickness and having openings spaced along its length to receive said shaped charges, said strip having radially extending slots about said openings to receive said projections, said projections having grooves therein to form lugs to engage opposite sides of said strip when said shaped charges are rotated relative to a said strip, said strip having radial extensions extending inwardly of said openings to a lesser given diameter than the normal diameter of said openings, said extensions being inclined relative to at least one plane defined by an outer side surface of said strip so that said openings have portions of different diameters adjacent the respective side surf-aces of said strips, said shaped charges having portions of different diameters corresponding generally to the port ons of different diameters of said openings, thereby permitting insertion of said charge devices from only one side of said strip, said blasting cord extending along the length of said strip and through said receiving openings so as to hold shaped charges in fixed rotated position, thereby preventing release of said shaped charges from said strip.

9. Perforating apparatus for use in a Well bore comprising a plurality of capsu-lated shaped charges having spaced radial projections and a rear end with a blasting cord receiving opening, a blasting cord sized for retention in said primacord receiving openings in the rear ends of said shaped charges, and an integral strip of infrangible material of a given thickness and having openings spaced along its length to receive said shaped charges, said strip having radially extending slots about said openings to receive said projections, said projections having grooves therein to form lugs to engage opposite sides of said strip when said shaped charges are rotated relative to a said strip, said strip having radial extensions extending inwardly of said openings to a lesser given diameter than the normal diameter of said openings, said extensions being displaced relative to at least one plane defined by an outer side surface of said strip so that said openings have portions of different diameters adjacent the respective side surfaces of said strips, said shaped charges having portions of different diameters corresponding generally to the portions of different diameters of said openings, thereby permitting insertion of said charge devices from only one side of said strip, said blasting cord extending along the length of said strip and through said receiving openings so as to hold shaped charges in fixed rotated position, thereby preventing release of said shaped charges from said strip.

10. Perforating apparatus for use in a well bore comprising: an elongated strip member having a given thickness defined between spaced plane surfaces, said strip having openings spaced along its length, said strip having radially extending slots about said openings, said strip having radial extensions extending inwardly of said openings, said extensions being arranged relative to one of said plane surfaces so as to decrease the diameter of the opening at said one plane surtace relative to the normal diameter of such opening at said other plane surface; a plurality of shaped charge capsule devices having spaced radial projections arranged for passage through said slots and a rear end with a blasting cap receiving opening said projections having grooves therein sized to fit the normal diameter of said openings and align portions of said projections on either side of said strip, each of said devices having an interference portion arranged relative to the width of said grooves in said projections, said interference portion being sized to be received Within an opening from the side of said strip wherein such opening has a normal diameter to permit alignment of said grooves: with said opening so that a charge device is rotatable into a position wherein said grooved projections secure such charge device to said strip, said interference portions preventing alignment of said projections relative to said strip by interference with said radial extensions, thereby preventing insertion of a charge device from the side of said strip wherein such opening has a decreased diameter; and blasting cap received by said prirnacord receiving openings.

11. Perforating apparatus for use in a well bore comprising: an elongated, thin, continuous strip member having a plurality of openings spaced from one another along the length of the strip member; a plurality of shaped charge devices respectively having an intermediate section with a portion sized to be received by a strip opening and having forward and rearward ends disposed along the axis of a device, each of said devices having attaching means on said intermediate section including a radially extending set of lugs, said lugs in a set being spaced axially of one another a distance corresponding generally to the thickness of said strip member, said strip having slots disposed about said openings torespectively receive one of said lugs of a set when said one lugs are introduced from one side of said strip member whereby said charge devices may be inserted into said strip openings and rotated, thereby permitting said sets of lugs to respectively engage opposite sides of said strip member, said strip member having projections extending inwardly of said openings to a lesser diameter than the diameter of said openings, said projections being oitset with respect to at least one plane defined by an outer side surface of said strip member, said charge devices each having portions arranged relative to the space between a set of lugs to engage said ofiset projections when the one of said lugs of a set is introduced from the other side of said strip member.

12. Perforating apparatus for use in a well bore comprising: an elongated, thin, continuous strip member having a plurality of openings spaced from one another along the length of the strip member; a plurality of shaped charge devices respectively having a generally conical configuration with an intermediate section having -a portion sized to be received by a strip opening and having forward and rearward ends disposed along the axis of a device, each of said devices having attaching means on said intermediate section including a radially extending set of lugs, said lugs in a set being spaced axially of one another a distance corresponding generally to the thickness of said strip member, said strip having slots disposed about said openings to respectively receive one of said lugs of a set when said one lugs are introduced from one side of said strip member whereby said charge devices may be inserted into said strip openings and rotated, thereby permitting said sets of lugs to respectively engage opposite sides of said strip member, said strip member having projections extending inwardly of said openings to a lesser diameter than the diameter of said openings, said projections being offset with respect to at least one plane defined by an outer side surface of said strip member, said charge devices each having portions arranged relative to the space between a set of lugs to engage said ofiset projections when the one of said lugs of a set is introduced from the other side of said strip member.

References Cited in the file of this patent UNITED STATES PATENTS 2,272,688 Catron Feb. 10, 1942 2,606,718 Mayo Aug. 12, 1952 2,717,366 Summerer Sept. 6, 1955 2,756,677 McCullough July 31, 1956 2,764,938 Harcus Oct. 2, 1956 2,833,213 Udry May 6, 1958 FOREIGN PATENTS 1,023,832 France Jan. 7, 1953 

6. PERFORATING APPARATUS FOR USE IN A WELL BORE COMPRISING A PLURALITY OF CAPSULATED SHAPED CHARGES HAVING SPACED RADIAL PROJECTIONS AND A REAR END WITH A BLASTING CORD RECEIVING OPENING, A BLASTING CORD SIZED FOR RETENTION IN SAID PRIMACORD RECEIVING OPENINGS IN THE REAR ENDS OF SAID SHAPED CHARGES, AND AN INTEGRAL STRIP OF INFRANGIBLE MATERIAL OF A GIVEN THICKNESS AND HAVING OPENINGS SPACED ALONG ITS LENGTH TO RECEIVE SAID SHAPED CHARGES, SAID STRIP HAVING RADIALLY EXTENDING SLOTS ABOUT SAID OPENINGS TO RECEIVE SAID PROJECTIONS, SAID PROJECTIONS HAVING GROOVES THEREIN TO FORM LUGS TO ENGAGE OPPOSITE SIDES OF SAID STRIP WHEN SAID SHAPED CHARGES ARE ROTATED RELATIVE TO A SAID STRIP, SAID STRIP HAVING RADIAL EXTENSIONS EXTENDING INWARDLY OF SAID OPENINGS TO A LESSER GIVEN DIAMETER THAN THE NORMAL DIAMETER OF SAID OPENINGS, SAID EXTENSIONS BEING TAPERED RELATIVE TO AT LEAST ONE PLANE DEFINED BY AN OUTER SIDE SURFACE OF SAID STRIP SO THAT SAID OPENINGS HAVE PORTIONS OF DIFFERENT DIAMETERS ADJACENT THE RESPECTIVE SIDE SURFACES OF SAID STRIPS, SAID SHAPED CHARGES HAVING TAPERED PORTIONS CORRESPONDING GENERALLY TO THE TAPERED EXTENSIONS IN SAID OPENINGS, THEREBY PERMITTING INSERTION OF SAID CHARGE DEVICES FROM ONLY ONE SIDE OF SAID STRIP, SAID BLASTING CORD EXTENDING ALONG THE LENGTH OF SAID STRIP AND THROUGH SAID RECEIVING OPENINGS SO AS TO HOLD SHAPED CHARGES IN FIXED ROTATED POSITION, THEREBY PREVENTING RELEASE OF SAID SHAPED CHARGES FROM SAID STRIP. 